Lewis and Clark's famous expedition to the Pacific Northwest in 1804 almost came to an untimely and deadly end. Half starved and almost frozen, the men staggered out of Idaho's snowy Bitterroot Mountains and into the camp of the Nez Perce Indians. Dayton Duncan and Ken Burns tell the story in Lewis and Clark: The Journey of the Corps of Discovery:

Lewis and Clark were the first white men ever to reach their homeland. In the absence of more prominent leaders, who were out on a war party, a chief named Twisted Hair had to decide what to do with the weak but wealthy strangers suddenly in their midst. According to the tribe's oral tradition, some of the Nez Perce proposed killing the white men and confiscating their boxes of manufactured goods and weapons. The expedition's rifles and ammunition, in particular, would have instantly made the Nez Perce the region's richest and most powerful tribe.

But … an Indian woman came to the Corps of Discovery's aid. As a young girl, she had been captured by an enemy tribe on the plains, who in turn sold her to another tribe farther to the east. Eventually she had been befriended and treated kindly by white people in Canada before escaping and making her way back to her own people. They called her Watkuweis-'Returned from a Faraway Country'-and for years she had told them stories about the fair-skinned people who lived toward the rising sun. She was aged and dying by the time the explorers arrived.

When she learned about possible plans to destroy the expedition, tribal tradition says, she intervened. "These are the people who helped me,"' she said. "Do them no hurt."

A stranger's simple act of kindness—years before—saved the lives of an entire expedition. A little kindness can have amazing and unexpected results.